#!/usr/bin/perl
use File::Find;

$|++;

my $path = '.';
my $cmd = 'file';
finddepth (\&wanted,$path);

# untested regex
my $regex =  qr/\Q.png$\E/i;

sub wanted {
  return unless -f; #-d for dir ops or comment out for both 
  
if ( /$regex/) { 
         print "$File::Find::name\n" 
    
          #do your ImageMagick processing here         

           }

}

__END__